Win7 (64 bit) driver for mini2440

I have download for this website the driver and install it 
but I get 
"
Windows cannot verify the digital signature for the drivers required for
this device. A recent hardware or software change might have installed a
file that is signed incorrectly or damaged, or that might be malicious
software from an unknown source. (Code 52)
"
why is it? 
also I can't connect to the device using the usb 
the DNW doesn't show me I can connect to it 

what do I need to in order to start working ?

Thanks ,